1. Field of the Invention
The present invention relates to a photoresist removing composition and particularly to a photoresist removing composition used in a wiring process of a semiconductor integrated circuit or a liquid crystal display (LCD).
2. Description of the Related Art
Semiconductor integrated circuits are produced by a process in which a photoresist is applied onto an inorganic substrate, a photoresist pattern is formed by exposure to light and subsequent development, the portions of the inorganic substrate not masked by the photoresist pattern are etched to form fine circuits by using the photoresist pattern as a mask, and then the photoresist is removed from the inorganic substrate. The photoresist remaining on the inorganic substrate is directly removed using a removing agent; or ashed to gasify organic components and remove the photoresist and then a still remaining photoresist residue is removed using a removing agent.
Objects to be removed by the photoresist removing agent are the photoresist layer applied onto the inorganic substrate, a photoresist layer remaining on the inorganic substrate after dry etching, and a photoresist residue after ashing. These photoresist layers and the photoresist residue is hereinafter referred to as a photoresist residue or the like.
Conventionally, as the removing agent for use in the above-described processes, acidic removing agents or alkaline removing agents have generally been used.
Examples of the acidic removing agent include a removing agent comprising arylsulfonic acids such as benzenesulfonic acid, toluenesulfonic acid, and xylenesulfonic acid, phenols, and organic solvents containing chlorine (U.S. Pat. No. 3,582,401) and a removing agent comprising aromatic hydrocarbons such as naphthalene, phenols, and arylsulfonic acids (Japanese Patent Application Laid-Open No. Showa 62(1987)-35357).
These acidic removing agents have low removing ability and easily corrode aluminum and copper which are frequently used as a wiring pattern material. Therefore, these agents are not suitable for the fine works to which strict dimensional accuracy (design rule) has been required in recent years. Moreover, because the solubility of these acidic removing agents in water is low, it is necessary that the product obtained after the removal of the photoresist be rinsed with an organic solvent such as alcohols, and subsequently washed with water. This causes a drawback in that the process is more complicated.
Examples of the alkaline removing agents include a removing agent comprising an addition product of ethylene oxide to an alkanolamine or a polyalkylenepolyamine, a sulfonic compound, and a glycol monoalkyl ether (Japanese Patent Application Laid-Open No. Showa 62(1987)-49355), and a removing agent comprising dimethyl sulfoxide as the main component, a diethylene glycol monoalkyl ether, and an organic hydroxyl compound containing nitrogen (Japanese Patent Application Laid-Open No. Showa 64(1989)-42653).
The alkaline removing agents have high removing power to the photoresist residue or the like compared with the acidic removing agents and have lower corrosion power to the wiring pattern materials. However, in recent hyperfine working technique, etching conditions of the wiring pattern materials become severe and the photoresist used in the etching tends to be deteriorated. Accordingly, the conventional alkaline removing agents have insufficient removing ability and the problem arises that the photoresist residue or the like remains on the inorganic substrate. Further, a width of the wiring pattern is narrower, therefore, it is required to reduce damages to the wiring pattern in a removing step. In this point of view, the conventional alkaline removing agents are also insufficient. Moreover, the conventional alkaline removing agent should be used at 80xc2x0 C. or more. Such high temperature results in volumes of vapor and mist, which is not desirable for a working environment.
In order to solve the above problems, there have been proposed a removing agent comprising alkanol amines or alkoxyamines or alkoxyalkanol amines, glycol monoalkyl ether, sugars or sugar alcohols, a quaternary ammonium hydroxide and water (Japanese Patent Application Laid-Open No. Heisei 8(1996)-262746) and a removing agent comprising alkanol amines or alkoxyamines or alkoxyalkanol amines, acid amides, sugars or sugar alcohols and water (Japanese Patent Application Laid-Open No. Heisei 8(1996)-202001). However, these removing agents have still insufficient removing ability to the photoresist residue or the like. Accordingly, a removing agent which has excellent removing ability and does not cause corrosion of the wiring pattern material in the inorganic substrate is required.
In addition, removing conditions such as a low removing temperature and a short removing time are required to make the working convenient.
An object of the present invention is to provide a photoresist removing composition capable of removing a photoresist layer applied onto an inorganic substrate, a remaining photoresist layer after dry etching and a photoresist residue after ashing easily at a low temperature in a short time, during which a wiring pattern material is never corroded and is processed hyperfinely to manufacture a highly precise circuit pattern.
Through intense studies to solve the problems mentioned above, the present inventors found that a photoresist removing composition comprising a quaternary ammonium hydroxide, a water-soluble amine and alkylpyrrolidone or a photoresist removing composition further comprising an anticorrosive can remove a photoresist residue or the like easily at a low temperature in a short dime during a patterning process of a semiconductor integrated circuit, and the composition also has extremely excellent properties of noncorrosiveness and operational convenience, thus the present invention has been completed.
Accordingly, the present invention provides a photoresist removing composition comprising the quaternary ammonium hydroxide, the water-soluble amine and the alkylpyrrolidone or a photoresist removing composition comprising the quaternary ammonium hydroxide, the water-soluble amine, the alkylpyrrolidone and the anticorrosive.